My first question was if it is doable. Thank you for the answer;)
My second question is does anyone have an example of the part design. I can’t overmold this do to cost. Our keypads come from China, but we mold our enclosures here. So I need to do this two parts and assemble it.
we used that for bike computers in the 90’s (yea everything i did was in the 80’s 90’s) There are 2 options a dome switch to make the contact or conductive rubber dot applied to the base of each keypad.
“Its radical design appealed to only a small segment of the population and the production of the rubberized keyboard proved too costly to ensure mass success. …Bellini created a calculator that was the aesthetic pinnacle of consumer electronics in the early 1970s.” - Phaidon Design Classics
Here is a more recent interpretation by Naoto Fukasawa, but I can’t tell if it’s all one piece:
Exhibit 1: I the Olivettis are using mechanical switches that are covered by a rubber membrane. While very cool, it’s not what I am using. Our products typically use switches that make contact with the PCB to make the connection. As shown on the right of my drawing.
Exhibit 2: What I want is this kind of look. A hard plastic shell with an area of rubber with my buttons contained in the rubber area.
Does this help explain what I’m looking for a little more?
What you’re really trying to do is a conventional silicone keypad, but without the plastic bezel on top. Normally this would be a bad idea because the silicone is so flexible that the keys would shift around and wouldn’t have the proper feel or travel.
But since it shows you want a very low/flat key it shouldn’t be too much of a problem. You will just use a rubber keypad + a larger carbon puck (Those little black things on the bottom of most conventional calculator keypads) or a metal snap dome (better tactile feel). The issue becomes how the rubber piece gets fastened to the rest of the unit and assembled. It may also wear faster than you want, so if durability is an issue you should strongly consider your reasons for using it.
Your first sketch will work as long as you have to place 2 side adhesive in between the silicone rubber and the enclosure - It seems that your keypad base is so thin - it might can’t hold the force reaction during switching.
Beware, the exposed membrane might be rip off by sharp pointed devices.